Transfer of cartridges containing flat articles

A sorting system for flat articles comprising:

• a plurality of cartridges each sized to hold a stack of the flat articles, each cartridge including a bottom, sidewalls, and a pivotable door mounted to the sidewalls, the cartridge including a latch for securing and releasing the door and at least one actuating member for opening the door,
• an array of output compartments, each output compartment being configured to receive and support a cartridge and including a projection for engaging and unlocking the latch as a cartridge is inserted into the compartment, and at least one cam member for engaging the door actuating member and opening the door as the cartridge is positioned in the compartment to receive sorted articles, the array of output compartments being arranged in rows and columns;
• means for sorting flat articles into selected ones of the compartments, the flat articles being received in cartridges positioned in the output compartments;
• a transfer robot, the transfer robot including a vertical support column mounted on a rail for horizontal movement along the length of the array, a first motor coupled to the transfer robot for moving the robot along the rail, a cartridge support platform mounted on the support column for vertical movement along the support column, a second motor coupled to the support platform for moving the platform vertically along the support column, the cartridge support platform including an end effector operative to insert a cartridge into a compartment and extract a cartridge from a compartment, an actuator for actuating the end effector, an extensible support for supporting cartridges as the cartridges are inserted and removed and an actuator for actuating the extensible support;
• a sensor, the sensor detecting when a cartridge positioned in a compartment is substantially full of flat articles and generating a signal indicating that the cartridge is substantially full;
• and
• a supervisory computer being programmed to direct the transfer robot to remove the cartridge from the compartment in response to the signal indicating the cartridge is full.